1. Field of the Invention
This invention relates generally to an information signal processing system and is directed more particularly to an information signal processing system suitable for use with pattern recognition systems.
2. Description of the Prior Art
With prior art pattern recognition systems, a picture, pattern or the like is divided into, for example, 120 horizontal scanning lines by a television camera and then provided as video signals. Then, the video signals are converted into a sampled signal each of which has 120 digital values at every one horizontal scanning line, and accordingly a single picture frame has 14,400 digital values. Further, by adaptation of stroke method or pattern matching method or the like to this sampled signal, the features of the pattern, characters or the like of a single picture frame are extracted to establish the recognition thereof.
As a result, under the conventional systems, the quantities of the digital values for a single picture frame are extremely large, so that the construction of the prior art pattern recognition systems is complicated and has a disadvantage because a long processing time is inevitable.
Accordingly, in order to solve such a disadvantage, it is desirable to minimize the sampling frequency which equals the number of digital values of one picture. However, in doing so, the resolution ability of patterns, characters, etc. within one picture, is reduced and is undesirable.
Further, as another method of solution, the adaption of band compression methods may be considered, but the reduction ratio thereof is at most about 1/10 and hence the methods are not remarkably practical.